This invention relates to a rotary type hydraulic servo-mechanism, and, more particularly, it is concerned with a hydraulic rotary servo-mechanism of a type, wherein an oil chamber is provided to cause a torque which hinders rotational force of an input shaft when it is actuated.
There has already been proposed a rotary type hydraulic servo-mechanism which is constructed with a hollow cylindrical casing closed at both open ends thereof by two end blocks and having one or more radially inwardly projecting partition walls on the inner surface thereof, the partition walls extending axially in the casing, an input shaft passing axially and concentrically through the casing, a driven output member rotatably mounted on the input shaft within the casing with one end thereof being extended axially through and out of one of the end blocks as an output portion and having one or more radially outwardly projecting partition walls extending axially from the member, the partition walls of which are installed in such a manner that the outer surfaces thereof are fluid-tightly but slidably movable along the inner surface of the casing, the former and latter partition walls defining therebetween at least two chambers formed between the casing and the output member, a servo-mechanism provided between the opposing sliding surface of the input shaft and the output member, and hydraulic fluid supply and discharge passages connected to the servo-mechanism to supply and discharge hydraulic fluid to and from the chambers under the conrtol of the servo-valve mechanism which operates in response to rotation of the input shaft relative to the output member.